The qualified wave soldering temperature curve must meet with:
1: The temperature range of the bottom of the PCB in the preheating zone is 90-120oC.
2: The tin point temperature range during soldering is: 245±10℃
3. The temperature between CHIP and WAVE cannot be lower than 180℃
4. PCB tin immersion time: 2-5sec
5. The preheating temperature ramp rate of PCB board bottom ≦5oC/S
6. The temperature of the PCB board at the outlet of the furnace is controlled below 100 degrees
The temperature and duration of each zone are also determined by the temperature setting of each zone of the equipment, the temperature of the molten solder and the running speed of the conveyor belt. Wave soldering temperature curve measurement still needs to be determined by testing methods, and the basic process is similar to the reflow curve measurement. Because the front side (Top-orBoard) of PcB is densely mounted, the temperature curve can only detect the surface temperature. During the test, determine the conveyor belt speed, and then record the temperature of three points less on the test board. Repeatedly adjust the heater temperature value so that the temperature of each point reaches the set curve requirement, and then carry out the installation test and make the necessary adjustments. When preparing the process file, in addition to recording the heating temperature curve setting, it is generally necessary to record the flux and its spreading process parameters (foam height, spray angle, pressure, density control requirements and flux rationality, etc.), solder wave parameters, and solder picking These are the main process parameters of wave soldering, such as requirements for testing and slag removal.